Snow blower control systems



March 12, 1957 J. w. LOGAN, JR 2,784,928

SNOW BLOWER CONTROL SYSTEMS Filed May 11, 1955 2 Shee ts-Sheet 1 I MI 4EN TOR. ug I N V His ATTORNEY John "(Logan .ln

March 12, 1957 J. w. LOGAN, JR

snow BLOWER CONTROL SYSTEMS 2 Sheets-Sheet 2 I '20 VA. P4

Filed May 11, 1955 ll --l To Hanii'ald 012 1Zal'l4 INVENTOR.

John W Loyan Ji' BY 10. A, W.

HIS ATTORZVEY To fiam'fald 011 Rail 3 1 United States PatentO SNOWBLOWER CONTROL SYSTEMS John W. Logan, Jr., Forest Hills, Pa., assignorto Westinghouse Air Brake Company, Wilmerding, Pa., a corporation ofPennsylvania Application May 11, 1955, Serial No. 507,582

11 Claims. (Cl. 246-428) My invention relates to automatic snow removingdevices, and particularly to an automatic snow blower con trol systemfor removing accumulated or falling snow, or other foreign material,from between the switch points and stock rails of a railroad switch.

It has been the practice in most instances in the past to remove snowfrom railroad switches by the use of heaters or :burners located atstrategic points along the rails of the switch for melting the snow inthose areas where accumulated and packed snow interferes with the properoperation of the railroad switch. The heater or burner installations atthe railroad switches are expensive to install and operate, the heateror burner systems requiring constant care and watchfulness during theiroperation. With snow melting devices there is the problem of disposingof the melted snow, proper drainage of the water being seriouslyhindered by the subsequent formation of ice.

It is therefore an object of my present invention to provide apparatusfor the removal of snow or other foreign material from between theswitch points and stock rails of a railroad switch before the snow orother material has accumulated to a degree where it interferes with theproper operation of the switch.

A further object of my invention is to provide an autov matic snowblower system for removing the snow or other material from between thepoints and rails of a railroad switch by timed blasts of air directedbetween the movable points and fixed rails of the railroad switch.

Another object of my invention is to provide an automatic snow blowersystem of compact and rugged design comprising few and simple partsinexpensive to manufacture and readily assembled and disassembled, theparts being such that the timed intervals of the delivery of air blaststo clear the snow may be readily altered to provide a cycle of operationsuited for the particular need.

In carrying out my invention, I provide a series of nozzles formanifolds which are secured to the inner surfaces of the stock railwebs, the nozzles being directed toward the movable points of therailroad switch. The manifolds are connected by suitable pipe lines toan electropneumatic control valve which is opened and closed at timedintervals. The control valve of my control system is connected in theair line of a reservoir or tank for supplying air under compression tothe manifold nozzles. The reservoir or tank is charged from a suitablesource such, for example, as an air compressor, or from the air linesprevalent in railroad yards.

My novel snow blower control system includes two pressure responsivedevices connected in the discharge line of the pressure reservoir, eachof the devices controlling a pair of electrical contacts. The pressureactuated cont acts are connected in a relay circuit for controlling theoperation of the control valve of the system. With fluid pressure in thesystem above a predetermined value, the electrical circuit is such thatoperation of the blower may be initiated from a remote point either byway of a push button, a relay, or by control devices of various kinds.

2,784,928 Patented Mar. 12, 1957 The electrical contacts controlled bythe pressure re= sponsive devices in the reservoir discharge line areactuated by their respective pressure devices so that one pair ofcontacts is closed when the fluid pressure falls below the onepredetermined value and the other pair of contacts is closed below asecond predetermined pres= sure value. The opening and closing of thepressure actuated contacts control the operation of the relay to providea cycle of operation for the control valve which permits timed blasts ofair to be directed at the switch points to clear away the snow or othermaterial tending to hamper the proper operation of the switch. The snowblower control system described is further characterized by itsadaptability to the various requirements of particular installations.

I shall describe two forms of automatic snow blowers embodying myinvention, and shall then point out the novel features thereof inclaims.

In the accompanying drawings wherein similar reference characters referto similar parts in each of the several views,

Fig. l is a plan view of a typical railroad switch layout including mynovel automatic snow blower.

Fig. 2 is a sectional view along the line 11-11 of Fig. 1.

Fig. 3 is a side elevational view of a stock rail of a railroad switchshowing the installation of the manifold and the snow blower nozzles.

Fig. 4 is a schematic diagram of my novel automatic snow blower control,while i Fig. 5 is a schematic diagram of a modification of my snowblower control whereby the blasts of air are directed only at the openswitch points.

Referring now in detail to the drawings, the reference character 1designates in general a railroad switch secured in the usual manner torailroad ties 2, the switch comprising the fixed rails 3 and 4 and themovable rails 5 and 6. The movable rails 5 and 6 are interconnected by atie rod 7 which is connected by way of the usual coupling 8 to a throwrod 9 of a switch movement 10 secured to the ties 2. The movable rail orswitch point 6 has secured thereto a circuit controller operating rod11, the outer ends of the operating rod being connected to the crank 12of a circuit controller 13 secured to the ties 2.

Secured to a suitable foundation 14 adjacent the fixed rail 3 andbetween two ties 2, is a snow blower control box 15 housing theautomatic control elements illustrated schematically in Fig. 4. Theelements of the control box are connected to a supply of compressed airvia a suitable pipe or conduit 16. The conduit 16 is connected to astorage or reservoir tank 17 secured to a suitable foundation (notshown), the inlet of the tank being connected through a throttling valve18 to a compressed air supply source (not shown). The elements of thecontrol box 15 are connected by pipe lines: 19 to manifolds 20 securedto the inner surface of the webs of stock rails 2 and 3 (Fig. 3) byclips 21 fastened to the rails as by bolts 22, the pipe lines passingthrough suitable openings 4a provided in the rail webs. The manifolds 20are provided with a plurality of nozzles 23 facing in the directiontoward the switch points to direct blasts of air toward the points toblow away any accumulation of snow or other particles as, for example,sand or cinders, from between the switch points and the stock rails.

Referring now in detail to Fig. 4 illustrating schematically theelements of my novel snow blower control system, the conduit 16 from thefluid pressure reservoir 17 is connected to the inlet conduit 24 of anelectropneumatic control valve 25 of a standard design, the outlet ordischarge port 26 of the control valve being connected to a manifoldconduit 19. Connected into the conduit 16 are two T-connections 27 and28 serving as connections for two pressure responsive devices orswitches 29 and of the Bourdon type. The pressure responsive switch 29is preset or adjusted to close its contacts 31-32 when the pressure inthe reservoir conduit falls below a predetermined value, while thepressure 31-32 when the pressure falls below 55 pounds per square inchand with the pressure switch 30 set to close contacts 33-34 when thepressure in the system falls below 80 pounds per square inch.

The closing and opening of the contacts 31-32 and 33-34 by theirrespective pressure responsive devices control the operation of a relay35. One end of the operating coil of the relay is connected to the Nterminal 'of a suitable source of power supply, while the other end isconnected by lead 36 to the contact 32, and by a lead 37 over the frontcontacts 38 of the relay to the "contact 34 of the pressure switch 30.The contact 31 of the pressure switch 29 is connected to a common lead'40 and through normally open contacts 41-42 to the "B terminal of thepower supply. The contacts 41-42 may be closed and opened either locallyor at a remote point by manual means as, for example, a push button, orby a relay or other control device.

The common lead 40 is connected to the contact 33 of the pressure switch30 and by a lead 44 over the back 'contact 45 of the relay to one end ofa solenoid operating coil 46 for the control valve 25. The other end ofthe operating coil 46 is connected to the N terminal of the powersupply.

In the operation of the automatic snow blower control described, thethrottling valve 18 is adjusted so that the air reservoir 17 is chargedfrom the air supply source within a suitable time after the air has beendischarged by the operation of the control valve 25. By way of exampleand with the reservoir 17 connected to a suitable air source, thethrottling valve 18 is adjusted so that it takes approximately thirtyseconds to build up a pressure of 80. pounds per square inch in thereservoir.

With pressure in the reservoir above the preferable predeterminedpressure, the contacts 31-32 and 33-34 will beheld open by theirrespective pressure responsive members 29 and 30. Closing the contacts41-42 by any suitable means will complete an energizing circuit for thesolenoid operating coil 46 from the B terminal "of the power supply overthe leads and 44, over the closed back contacts of the deenergized relay35 to "the N terminal of the power supply. The energization of theoperating coil 46 will open the control valve 25 to permit the air underpressure to flow through the delivery duct 19 to the nozzle manifolds 20secured to the stock rails 3 and 4. The pressure in the system isquickly reduced upon opening of the control valve 25.

When the pressure within the system falls below 80 pounds per square inas the air is delivered to the 'nozzles 23, the contacts 33-34 of thepressure switch 30 close. A holding circuit is thus partially completedfor the deenergized relay 35 from the B terminal of the power supply,through lead 40 and resistor 43, the closed contacts 33-34 to the openfront contacts 38 of the 'relay. The continued delivery of the air tothe snow blower nozzles 23 Will reduce the pressure in the system stillfurther until the pressure falls below the previously indicated pressureof pounds per square inch. The pressure switch 29 will then close tocomplete an energizing circuit for the relay 35 from the B terminal ofthe power supply, through lead 40, over the closed contacts 31-32 andthrough the relay coil to the N terminal of the power supply. Theenergized relay 35 will now open its back contact 45 to deenergize thesolenoid operating coil 46 of the control valve 25, thereby cutting offthe air supply to the snow blower nozzles 23. The energized relay alsocloses its front contact 38 to complete a holding circuit for the relayover the closed contacts 33-34 of the pressure switch 30.

With the air supply cut off from the snow blower nozzles 23, the airpressure in the reservoir 17 will be built up again from the compressedair supply source. When the pressure exceeds 55 pounds per square inch,the pressure switch 29 will open its contacts 31-32. The relay, however,will be held energized by the stick or holding circuit previouslydescribed over the front contact 38 and the contacts 33-34 of thepressure switch 30. When the pressure in the reservoir again exceedspounds per square inch, the pressure switch 30 opens the contacts 33-34to deenergize the relay 35. The back contact 45 of the relay is againclosed to complete the energizing circuit for the solenoid operatingwinding 46 of the control valve 25. The cycle of operation is repeatedas long as the contacts 41-42 remain closed, the air being delivered tothe nozzles in the form of blasts of about three seconds-duration with adelay between blasts while the resorvoir 17 is being recharged of abouta thirty-seconds duration. It Will be appreciated that a differenttiming cycle may be readily provided by adjustment of the throttlingvalve 18 in the charging line of the reservoir 17 and by adjusting thepressure switches 29 and/ or 39 so that the contacts 31-32 and/ or 33-34will be closed and opened at pressures other than those hereinspecified.

In Fig. 5 of the drawings I have illustrated a modification of my novelsnow blower control whereby blasts of air are directed at the openswitch points only. In the modification illustrated, two control valves25a and 25b are connected to the reservoir outlet conduit 16. Thedelivery line 19a of valve 25a is connected to the manifold 20 securedto the stock rail 3 of the railroad switch 1, while the delivery line19b of the valve 25b is connected to the manifold 20 secured to thestock rail 4 of the switch. The solenoid operating coils 46a of thecontrol valves are connected by leads 47a and 471) through circuitcontroller contacts 48a and 48b, re-

spectively, through a common lead 49 to the back contact 45 of the relay35. As illustrated in Fig. 5, the circuit controller operating rod 11movable with the switch points closes the circuit controller contacts48a while opening the contacts 48b when the railroad switch is in itsnormal position as illustrated in Fig. l of the drawings. The energizingcircuit for operating coil 46a of the control valve 250 may thus becompleted over the closed circuit controller contacts 48a so that air ispassed through the delivery line 19a to the open point 5. When theswitch 1 is in its reverse position with the point 5 against the stockrail 3 and the point 6 open, the circuit controller contacts 48a areopen and the contacts 481) closed by the circuit controller operatingrod. Only the control valve 2512 will be operated in this position ofthe switch 1, the blasts of air being delivered to the open point 6 ofthe switch. It will be appreciated that by selectively controlling theair delivered to the nozzle manifolds so that blasts of air are directedonly toward the open switch point, only half the quantity of air isrequired in keeping the switch 1 clear of snow or other material.

The automatic snow blower control system I have provided forms a compactunit of rugged design comprising few parts inexpensive to manufactureand readily assembled or disassembled, the control system providing apositive and accurate control of the air blasts for removing the snowfrom between the movable points and stock rails of a railroad switch. Itwill be readily appreciated that my novel control for snow blowers andthe like is not necessarily limited to the clearing of railroad switchesbut may readily be used in controlling the air blasts for clearingr-ight-of-ways, roadways, runways and the like of snow or otheraccumulater or accumulating material. The control system is such thatany desired timing cycle for the delivery of the air blasts to themanifold nozzles may 'be readily set or altered to meet particular conditions at different locations, the control system being such that manualor automatic initiation of the blower operation may be controlled eitherlocally or fromja remote control point.

Although I have herein shown and described two forms of a snow blowercontrol system embodying my invention, it is understood that variouschanges and modifications may be made therein within the scope of theappended claims without departing from the spirit and scope of myinvention.

Having thus described my invention, what I claim is:

l. A fluid pressure operated device comprising at least one nozzledirected toward a predetermined area, a source of fluid pressure, areservoir connected to said-source and to said nozzle, anelectromagnetically operated control valve for controlling the exhaustof fluid from said reservoir to said nozzle, pressure actuated means foroperating said control valve including electrical contacts actuated whenthe fluid pressure of said reservoir falls below a first predeterminedpressure and when said pressure falls below a second predeterminedpressure, and electrical circuit including said pressure actuatedcontacts, and relay means in said circuit controlled by said pressureactuated contacts for opening said control valve when the pressure insaid reservoir is above the first predetermined pressure and maintainingthe control valve open while the pressure falls to the secondpredetermined pressure, said relay controlling the closing of saidcontrol valve when the pressure falls below the second predeterminedpressure and maintaining the control valve closed until the pressure insaid reservoir rises to the first predetermined pressure.

2. A fluid pressure operated device comprising at least one nozzledirected toward a predetermined area, a source of fluid pressure, areservoir connected to said source and to said nozzle, means forcontrolling the charging rate of said reservoir from said source; acontrol valve includingan electromagnetic operator for controlling theexhaust of fluid from said reservoir to said nozzle, first pressureoperated contacts actuated when the reservoir pressure falls below afirst predetermined pressure, second pressure operated contacts actuatedwhen the reservoir pressure falls below a second predetermined pressure,a relay including front and. back contacts, and an electrical circuitfor the electromagnetic valve operator, the pressure operated contactsand the relay; said electromagnetic operator being energized over a backcontact of the relay to open said valve when the reservoir pressure isabove the first predetermined pressure and maintained energized as thereservoir pressure falls below the first- :predeterrnined pressure tothe second predetermined pressure, said electromagnetic operator beingdeenergized to close said valve upon energization of said relay whenthe-reservoir pressure falls below said second predetermined pressureand maintained deenergized during the recharging of said reservoir untilthe reservoir pressure is higher than first predetermined pressure.

3. A fluid pressure operated device comprising at least one nozzledirected toward a predetermined area, a source of fluid pressure, areservoir connected to said source and to said nozzle, 21 control valveincluding an electromagnetic operator for controlling the exhaust offluid from said reservoir to said nozzle, and an electrical circuit forcontrolling the energization of said electromagnetic operator, includinga first pair of pressure operated contacts actuated when the reservoirpressure falls below a first predetermined pressure, a second pair ofpressure operated contacts actuated when the reservoir pressure fallsbelow a second predetermined pressure lower than said firstpredetermined pressure, a relay including front and back contacts, andmeans for energizing said electromagnetic operator over a relay contactto open said valve when the reservoir pressure is above the firstpredetermined pressure, said relay being energized to open theenergizing circuit of said electromagnetic operator upon actuation ofsaid second pair of pressure operated contacts when the reservoirpressure falls below the second predetermined pressure and beingmaintained energized over a relay contact and the actuated first pair ofpressure operated contacts as the reservoir pressure builds up to thefirst predetermined pressure. 4. A fluid pressure operated devicecomprising at lea one nozzle directed toward a predetermined area, asource of fluid pressure, a reservoir connected to said source and tosaid nozzle, a control valve including an electromagnetic operator forcontrolling the exhaust of fluid from said reservoir to said nozzle, andan electrical circuit for controlling the energization of saidelectromagnetic operator, including a first pair of pressure operatedcontacts adapted to close when the reservoir pressure falls below afirst predetermined pressure, a second pair of pressure operatedcontacts adaptedto close when the reservoir pressure falls below asecond predetermined pressure lower than said first predeterminedpressure, a relay including front and back contacts, and means forenergizing said electromagnetic operator over a back contact of saidrelay to open said valve when both pairs of pressure operated contactsare open, said relay being energized to open the energizing circuit ofsaid electromagnetic operator upon closure of said second pair ofpressure operated contacts and being maintained energized over a frontcontact of the relay as long as the first'pair of pressure operatedcontacts remains closed. 5. A fluid pressure operated device comprisingat least one nozzle directed toward a predetermined area, a source offluid pressure, a reservoir connected to said source and to said nozzle,a control valve including an electromagnetic operator for controllingthe exhaust of fluid from said reservoir to said nozzle, and anelectrical circuit for controlling the energization of saidelectromagnetic operator including normally open controlling contacts, afirst pair of pressure operated contacts adapted to close when thereservoir pressure falls below a first predetermined pressure, a secondpair of pressure operated contacts adapted to close when the reservoirpressure falls below a second predetermined pressure lower than saidfirst predetermined pressure, and a relay including front and backcontacts, said electromagnetic operator being energized over a backcontact of said relay to open said valve upon closure of the controllingcontacts when both pairs of pressure operated contacts are open, saidrelay being energized to open the energizing circuit of saidelectromagnetic operator upon closure of said second pair of pressureoperated contacts and being maintained energized over a front contact ofthe relay as long as the first pair of pressure operated contactsremains closed.

6. A fluid pressure operated device comprising at least one nozzledirected toward a predetermined area, a source of fluid pressure, areservoir connected to said source and to said nozzle, means forcontrolling the charging rate of said reservoir from said source, acontrol valve including an electromagnetic operator for controlling theexhaust of fluid from said reservoir to said nozzle, and an electricalcircuit for controlling the energization of said electromagneticoperator including normally open controlling contacts, a first pair ofpressune operated contacts adapted to close when the reservoir pressurefalls below a first predetermined pressure, a second pair of pressureoperated contacts adapted to close when the reservoir pressure fallsbelow a second predetermined pressure lower than said firstpredetermined pressure, and a relay including front and back contacts,said electromagnetic operator being energized over a back contact ofsaid relay to open said valve upon closure of the controlling contactswhen both pairs of pressure operated contacts are open, said relay beingenergized to open the energizing circuit of said electromagneticoperator upon closure of said second pair of pressure operated contactsand being maintained energized over a front contact of the relay as longas the first pair of pressure operated contacts remains closed.

7. A fluid pressure operated blower for a railroad switch comprising, atleast one nozzle for each switch point directed to deliver a fluid blastbetween the switch point and the adjacent rail to clear snow, sand andother material from between the switch point and the rail, a source offluid under pressure, a reservoir connected to said source and to eachof said nozzles, a control valve for .each nozzle including anelectromagnetic operator for controlling the exhaust of fluid from saidreservoir to each of said nozzles, and an electrical circuit forselectively controlling the energization of each of the electromagneticoperators including circuit controller contacts selectively actuatedwhen the switch occupies its normal position and predetermined pressureto open the selected control valve for exhausting the reservoir fluidbetween the one point and its adjacent rail.

.8. A fluid pressure operated blower for a railroad switch comprising,at least one nozzle for each switch point directed to deliver a fluidblast between the switch point and the adjacent rail to clear snow, sandand other material from between the switch point and the rail, 8.:source of'fluid under pressure, a reservoir connected to said sourceand to each of said nozzles, a control valve for each nozzle includingan electromagnetic operator for controlling the exhaust of fluid fromsaid reservoir to each of said nozzles, and an electrical circuit forselectively controlling the energization of each of the electromagneticoperators including circuit controller contacts selectively actuatedwhen the switch occupies its normal position and its reverse position,pressure actuated contacts actuated when the pressure within thereservoir falls below a predetermined pressure, and means for energizingone of said electromagnetic operators over the selectively actuatedcircuit controller contacts when the pressure is above the predeterminedpressure to open the selected control valve for exhausting the reservoirfluid between the one point and its adjacent rail, said last meansincluding means for deenergizing the selectively energizedelectromagnetic operator when the reservoir pressure falls below thepredetermined pressure and for maintaining the selected operatorenergized until the reservoir pressure again reaches the predeterminedpressure.

9. A fluid pressure operated blower for a railroad switch comprising atleast one nozzle for each switch point directed to deliver a fluid blastbetween the switch point and the adjacent rail to clear sand, snow orother debris from between the switch point and the rail, a source offluid pressure, a reservoir connected to said source and to each of saidnozzles, a control valve including an electromagnetic operator for eachnozzle for controlling the exhaust of fluid from said reservoir to eachof said nozzles, and an electrical circuit for controlling theenergization of said electromagnetic operator including a first pair ofpressure operated contacts adapted to close when the reservoir pressurefalls below a first predetermined pressure, a second pair of pressureoperated contacts adapted to close when the reservoir pressure fallsbelow a second predetermined pressure lower than said firstpredetermined pressure, circuit controllercontacts selectively actuatedin accordance with the normal and reverse positions of the switchpoints, and a relay including front and back contacts, one of saidelectromagnetic operators being energized over the selectively actuatedcircuit controller contacts and over a back contact of said relay toopen the selected control valve when both pairs of pressure operatedcontacts are open, said relay being energized to open the energizingcircuit. of said selected electromagnetic operator upon closure of saidsecond pair of pressure operated contacts and maintained energized overa front contact 8 I of the relay as long as the first pair of pressureactuated contacts remains closed. I

10. A fluid pressure operated blower for a railroad switch comprising atleast one nozzle for each switch point directed to deliver a fluid blastbetween the switch point and the adjacent rail to clear sand, snow orother debris from between the switch point and the rail, a source offluid pressure, a reservoir connected to said source and to each of saidnozzles, means for controlling the charg' ing rate of said reservoirfrom said source, a control valve including an electromagnetic operatorfor each nozzle for controlling the exhaust of fluid from said reservoirto each of said nozzles, and an electrical circuit for controlling theenergization of said electromagnetic operator including a first pair ofpressure operated contacts adapted to close when the reservoir pressurefalls below a first predetermined pressure, a second pair of pressureoperated contacts adapted to close when the reservoir pressure fallsbelow a second predetermined pressure lower than said firstpredetermined pressure, circuit controller contacts selectively actuatedin accordance with the normal and reverse positions of the switchpoints, and a relay including front and back contacts, one of saidelectromagnetic operators being energized over the selectively actuatedcircuit controller contacts and over a back contact of said relay toopen the selected control valve when both pairs of pressure operatedcontacts are open, said relay being energized to open the energizingcircuit of said selected electromagnetic operator upon closure of saidsecond pair of pressure operated contacts and maintained energized overa front contact of the relay as long as the first pair of pressureactuated contacts remains closed.

11. A fluid pressure operated blower for a railroad switch comprising atleast one nozzle for each switch point directed to deliver a fluid blastbetween the switch point and the adjacent rail to clear sand, snow orother debris from between the switch point and the rail, a source offluid pressure, a reservoir connected to said source and to each of saidnozzles, means for controlling the charging rate of said reservoir fromsaid source, a control valve including an electromagnetic operator foreach nozzle for controlling the exhaust of fluid from said reservoir toeach of said nozzles, and an electrical circuit for controlling theenergization of said electromagnetic operator including normally opencontrol contacts, a first pair of pressure operated contacts adapted toclose when the reservoir pressure falls below a first predeterminedpressure, a second pair of pressure operated contacts adapted to closewhen the reservoir pressure falls below a second predetermined pressurelower than said first predetermined pressure, circuit controllercontacts selectively actuated in accordance with the normal and reversepositions of the switch points, and a relay including front and backcontacts, one of said electromagnetic operators being energized over theselectively actuated circuit controller contacts and over a back contactof said relay to open the selected control valve upon closure of thecontrol contacts when both pairs of pressure operated contacts are open,said relay being energized to open the energizing circuit of saidselected electromagnetic operator upon closure of said second pair ofpressure operated contacts and maintained energized over a front contactof the relay as long as the first pair of pressure actuated contactsremains closed.

References Cited in the file of this patent UNITED STATES PATENTSHollinger Oct. 14, 1930 Gilmore et al. Jan. 25, 19 55

